HE Lingkong，LI Chuanlei，LI Yanjie

School of Technology， Beijing Forestry University， Beijing 100083， China

Objective Previous studies have explored the mechanical response mechanisms of elongated flexible particles under uniaxial compression， shear， and mixing， using both experimental and simulation methods. However， research on elongated flexible particles with different arrangements and woven forms remains limited. To address this gap， the study explores the compressive strength of such particles with different arrangements and woven forms through triaxial compression simulations.

Methods Compared to traditional models， such as spherical chains， elliptical chains， and rod chains， the sphero-cylinder model can more effectively simulate the deformation behavior and mechanical properties of elongated flexible particles of different materials. Therefore， triaxial compression simulations were used to investigate the mechanics of these particles connected by sphero-cylinder elements under different arrangements and woven forms.

Results and Discussion Compared to vertically and horizontally arranged elongated flexible particles， randomly arranged ones generated higher bond forces and bond bending moments， leading to increased normalized deviatoric stress and solid volume fraction in the granular bed. Increasing the bond elastic modulus （E_b ） enhanced the bond force and normalized deviatoric stress of vertically arranged particles at initial axial strains， though its effect diminished at larger strains. For randomly arranged particles， higher E_b significantly elevated both the internal bond forces and inter-particle contact forces， further increasing the normalized deviatoric stress of the bed. However， horizontally arranged particles showed negligible changes in contact force and stress. Additionally， increasing the aspect ratio of randomly arranged particles or weaving them into a net structure greatly improved bond forces and inter-particle contact forces， resulting in higher normalized deviatoric stress and solid volume fraction of the granular bed.

Conclusion During triaxial compression， the overall mechanical strength of granular beds with elongated flexible particles is significantly impacted by particle arrangements and woven forms. The sensitivity of elongated flexible particles to Eb varies across different particle arrangements. E_b more markedly impacts the strength of the granular bed with randomly arranged elongated flexible particles， whereas the strength of granular beds with vertically and horizontally arranged particles is less affected. Granular beds with randomly arranged and woven elongated flexible particles exhibit superior overall strength enhancement compared to horizontal and vertical arrangements or non-woven forms.